> In conducting a regression analysis we have run into a strange problem.
> After doing a simple regression between a personality score and
> activation in our condition of interest, the results show a peak voxel
> at (-30, 63, 18). We can extract these values from the voxel for
> individual subjects by querying Matlab for the values of y, and the
> scatterplot of the values against personality scores is well-behaved.
> However, when I attempt to extract values from this same voxel under
> other conditions by using a script similar to the one posted by John
> Ashburner, SPM responds with a series of "NaN"s, as if the voxel was
> outside of the brain.
It sounds like you may need to convert from co-ordinates in mm, to
co-ordinates in voxels. If you use the Display button, then it will show you
both.
Best regards,
-John
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